Many geographic locations have dry spells and/or insufficient rainfall requiring turf and landscaping to be watered to maintain the proper health of the vegetation. Turf and landscaping are often watered utilizing an automatic irrigation system that includes a programmable controller that turns a plurality of valves ON and OFF to supply water through underground pipes connected to sprinklers. Golf courses, playing fields and other large areas typically require rotor-type sprinklers that eject a long stream of water via a single relatively large nozzle that oscillates through an adjustable arc. In many cases golf courses utilize a rotor-type sprinkler having a built-in valve. These sprinklers are referred to in the irrigation industry as valve-in-head sprinklers.
In many parts of the United States it is necessary to winterize an automatic irrigation system by blowing out the water from the pipes, valves and sprinklers using compressed air. This is done to prevent damage to these components that would otherwise occur if residual water were to freeze and break these plastic structures during expansion. However, frequently there are pockets or regions in the system that still have residual water even after maintenance personnel have connected pressurized air to the system for an extended period of time. One such region that is particularly susceptible to this type of freezing damage is the small chamber associated with a pilot valve in either a valve-in-head sprinkler or a separate valve connected to a pipe that leads to a plurality of sprinklers.